This type of protective vests is known, for example, from Melliand Textilberichte, No. 6, pages 463-468 (1981), in which it is pointed out that fabrics from fine aramid yarns (e.g., 220 or 440 dtex), afford better ballistic protection than fabrics from relatively coarse yarns. Because of the high costs of fine yarns, a fineness of 1100 dtex is generally used and, in order to offset the somewhat poorer ballistic properties, an increase in the total-area weight would have to be accepted. These titer data all refer to the total titer of the aramid yarns used.
It may be concluded from this literature reference that, the mass per unit area of all the layers of aramid fabrics employed being equal, the ballistic protection can be increased by reducing the total titer of the aramid yarns used or that, in order to afford the same ballistic protection by reducing the total titer of the aramid yarns employed, the total-area weight can be reduced and thereby the wearing comfort can be improved.
As a rule, the filaments of aramid yarns known heretofore have an individual titer between 1.61 dtex and 1.68 dtex. Recently, an aramid yarn also became known whose filaments have an individual titer of 1.58 dtex and which is used in ballistic laminates in combination with other yarns (U.S. Pat. No. 4,181,768). However, the ballistic properties of ballistic laminates and ballistic multi-layer fabrics cannot be compared with each other.